In modern cellular communication networks, such as the Long Term Evolution (LTE) networks, an Operation Support System (OSS) is provided for managing many aspects of the operation of the cells of the network. Typically, a network operator may select network equipment from more than one vendor, and it is therefore common for a cellular communication network to have two or more Operation Support Systems (OSS), each with a set of cells that are being managed by the respective Operation Support System (OSS).
Some features of the cells in a cellular communication network must be managed on a network-wide basis, and not just managed within each of the Operation Support System. One such feature is a cell identifier for cells in the communication network, since each cell must have a cell identifier that is unique compared with the cell identifiers of neighbouring cells belonging to any cell set. In modern communication networks, the number of physical cell identities (PCI) and scrambling codes (SC) available are limited, for example there are only 504 physical cell identities (PCI) available in a LTE network. These cell identities must be reused within the communication network cells in an optimal way.
In current communication systems the management of features such as cell identities in cellular communication networks with multiple operation support systems (OSS) and respective cell sets is generally handled by allocating reserved ranges to each Operation Support system for use in the cells in the communication network. For example, the network operator may reserve range X of physical cell identities (PCI)s for use in cells managed by OSSs C or D and these physical cell identities (PCI)s will not be used in cells managed by OSS A. Equally the network operator may reserve range Y of physical cell identities (PCI)s for use in cells managed by OSS A and G these physical cell identities (PCI)s will not be used in cells managed by OSS B.
Typically physical cell identities (PCI) and scrambling codes (SC) planning is carried out before cells and base stations are added to the wireless network.
Increasingly operational management of a communication network is being delegated to self organising network (SON) functions, typically operating in an Operation Support System node of the communication network. The use of such SON functions to manage aspects of the operation of the network assists the network operator in managing and operating the network.
The present invention seeks to mitigate or obviate at least some of the disadvantages of the prior art, and to provide a novel method and apparatus for assigning cell identifier values in a communication network and for managing the assignment of cell identifier values in a communication network.
Embodiments of the invention enable the automatic assignment of cell identifiers in a communication network in a border area between cell sets. Embodiments of the invention can be used to assign physical cell identities (PCI) in a Long Term Evolution (LTE) network. The need for manual administration in border areas between cell sets managed by different Operation Support Systems (OSS) can therefore be reduced or eliminated.